1. Field of the Invention
The present invention relates generally to satellite video systems, and in particular, to a method and apparatus for integrating a satellite television system and a wireless broadband system
2. Description of the Related Art
Satellite broadcasting of communications signals has become commonplace. Satellite distribution of commercial signals for use in television programming currently utilizes multiple feedhorns on a single Outdoor Unit (ODU) which supply signals to up to eight Integrated Receiver Decoders (IRDs) on separate cables from a multiswitch.
FIG. 1 illustrates a typical satellite broadcast system of the related art.
System 100 uses signals sent from Satellite A (SatA) 102, Satellite B (SatB) 104, and Satellite C (SatC) 106 that are directly broadcast to an Outdoor Unit (ODU) 108 that is typically attached to the outside of a house 110. ODU 108 receives these signals and sends the received signals to IRD 112, which decodes the signals and separates the signals into viewer channels, which are then passed to monitor 114 for viewing by a user. There can be more than one satellite transmitting from each orbital location and additional orbital locations without departing from the scope of the present invention.
Satellite uplink signals 116 are transmitted by one or more uplink facilities 118 to the satellites 102-106 that are typically in geosynchronous orbit. Satellites 102-106 amplify and rebroadcast the uplink signals 116, through transponders located on the satellite, as downlink signals 120. Depending on the satellite 102-106 antenna pattern, the downlink signals 120 are directed towards geographic areas for reception by the ODU 108.
Alternatively, uplink facilities 118 can send signals via cable 122 either in conjunction with uplink signals 116 or instead of uplink signals 116 to IRD 112, for display on monitor 114.
Each satellite 102-106 broadcasts downlink signals 120 in typically thirty-two (32) different frequencies, which are licensed to various users for broadcasting of programming, which can be audio, video, or data signals, or any combination. These signals are typically located in the Ku-band of frequencies, i.e., 11-18 GHz, or in the Ka-band of frequencies, i.e., 18-40 GHz, but typically 20-30 GHz.
As satellites 102-106 broadcast additional services and additional channels to the home, users will like and expect these additional services to be delivered at reasonable cost. Viewers and users of services, e.g., wireless networking, interne services, etc., will like and expect to have access to these services and integrate these services with other services, e.g., wireless telephone communications, etc.
FIG. 2 illustrates a typical ODU of the related art.
ODU 108 typically uses reflector dish 123 and feedhorn assembly 124 to receive and direct downlink signals 120 onto feedhorn assembly 124. Reflector dish 122 and feedhorn assembly 124 are typically mounted on bracket 126 and attached to a structure for stable mounting. Feedhorn assembly 124 typically comprises one or more Low Noise Block converters 128, which are connected via wires or coaxial cables to a multiswitch, which can be located within feedhorn assembly 124, elsewhere on the ODU 108, or within house 110. LNBs typically downconvert the FSS-band, Ku-band, and Ka-band downlink signals 120 into frequencies that are easily transmitted by wire or cable, which are typically in the L-band of frequencies, which typically ranges from 950 MHz to 2150 MHz. This downconversion makes it possible to distribute the signals within a home using standard coaxial cables. ODU 108 is typically mounted to home 110 via a mast 130 or other assembly which enables alignment of dish 123 with the various satellites 102-106.
The multiswitch enables system 100 to selectively switch the signals from SatA 102, SatB 104, and SatC 106, and deliver these signals via cables 124 to each of the IRDs 112A-D located within house 110. Typically, the multiswitch is a five-input, four-output (5×4) multiswitch, where two inputs to the multiswitch are from SatA 102, one input to the multiswitch is from SatB 104, and one input to the multiswitch is a combined input from SatB 104 and SatC 106. There can be other inputs for other purposes, e.g., off-air or other antenna inputs, without departing from the scope of the present invention. The multiswitch can be other sizes, such as a 6×8 multiswitch, if desired. SatB 104 typically delivers local programming to specified geographic areas, but can also deliver other programming as desired.
To maximize the available bandwidth in the Ku-band of downlink signals 120, each broadcast frequency is further divided into polarizations. Each LNB 128 can only receive one polarization at time, so by aligning polarizations between the downlink polarization and the LNB 128 polarization, downlink signals 120 can be selectively filtered out from travelling through the system 100 to each IRD 112A-D.
IRDs 112A-D currently use a one-way communications system to control the multiswitch. Each IRD 112A-D has a dedicated cable 124 connected directly to the multiswitch, and each IRD independently places a voltage and signal combination on the dedicated cable to program the multiswitch. For example, IRD 112A may wish to view a signal that is provided by SatA 102. To receive that signal, IRD 112A sends a voltage/tone signal on the dedicated cable back to the multiswitch, and the multiswitch delivers the SatA 102 signal to IRD 112A on dedicated cable 124. IRD 112B independently controls the output port that IRD 112B is coupled to, and thus may deliver a different voltage/tone signal to the multiswitch. The voltage/tone signal typically comprises a 13 Volts DC (VDC) or 18 VDC signal, with or without a 22 kHz tone superimposed on the DC signal. 13VDC without the 22 kHz tone would select one port, 13VDC with the 22 kHz tone would select another port of the multiswitch, etc. There can also be a modulated tone, typically a 22 kHz tone, where the modulation schema can select one of any number of inputs based on the modulation scheme.
To reduce the cost of the ODU 108, outputs of the LNBs 128 present in the ODU 108 can be combined, or “stacked,” depending on the ODU 108 design. The stacking of the LNB 128 outputs occurs after the LNB has received and downconverted the input signal. This allows for multiple polarizations, one from each satellite 102-106, to pass through each LNB 128. So one LNB 128 can, for example, receive the Left Hand Circular Polarization (LHCP) signals from SatC 102 and SatB 104, while another LNB receives the Right Hand Circular Polarization (RHCP) signals from SatB 104, which allows for fewer wires or cables between the LNBs 128 and the multiswitch.
The Ka-band of downlink signals 120 will be further divided into two bands, an upper band of frequencies called the “A” band and a lower band of frequencies called the “B” band. Once satellites are deployed within system 100 to broadcast these frequencies, each LNB 128 can deliver the signals from the Ku-band, the A band Ka-band, and the B band Ka-band signals for a given polarization to the multiswitch. However, current IRD 112 and system 100 designs cannot tune across this entire frequency band, which limits the usefulness of this stacking feature.
By stacking the LNB 128 inputs as described above, each LNB 128 typically delivers 48 transponders of information to the multiswitch, but some LNBs 128 can deliver more or less in blocks of various size. The multiswitch allows each output of the multiswitch to receive every LNB 128 signal (which is an input to the multiswitch) without filtering or modifying that information, which allows for each IRD 112 to receive more data. However, as mentioned above, current IRDs 112 cannot use the information in some of the proposed frequencies used for downlink signals 120, thus limiting the information transmitted in those downlink signals 120.
In addition, all inputs to the multiswitch are utilized by the current satellite 102-106 configuration, which inhibits upgrades to the system 100 for additional satellite downlink signals 120 to be processed by the IRD 112. Further, adding another IRD 112 to a house 110 requires a cabling run back to the ODU 108. Such limitations on the related art make it difficult and expensive to add new features, such as additional channels, high-definition programming, additional satellite delivery systems, etc., or to add new IRD 112 units to a given house 110.
Even if additional multiswitches are added, the related art does not take into account cabling that may already be present within house 110, or the cost of installation of such multiswitches given the number of ODU 108 and IRD 112 units that have already been installed. Although many houses 110 have coaxial cable routed through the walls, or in attics and crawl spaces, for delivery of audio and video signals to various rooms of house 110, such cabling is not used by system 100 in the current installation process.
FIG. 3 illustrates a single wire multiswitch embodiment of a satellite broadcast system of the related art.
ODU 108 can also be coupled to Frequency Translation Module (FTM) 500, also known as a Single Wire Multiswitch (SWiM) 500. SWiM 500 is coupled to power injector 502. SWiM 500 is able to directly support currently installed IRD 112 directly as shown via cables 124, as described with respect to FIGS. 1 and 2.
The SWiM 500 is also able to support new IRDs 508, via a network of signal splitters 504 and 506, and power injector 502. New IRDs 508 are able to perform two-way communication with SWiM 500, which assists IRDs 508 in the delivery of custom signals on private IRD selected channels via a single cable 510. Each of the splitters 504 and 506 can, in some installations, have intelligence in allowing messages to be sent from each IRD 508 to SWiM 500, and back from SWiM 500 to IRDs 508, where the intelligent or smart signal splitters 504 and 506 control access to the SWiM 500.
The two-way communication between IRDs 508 and SWiM 500 can take place via cable 510, or via other wiring, such as power distribution lines or phone lines that are present within house 110.
It can be seen, then, that there is a need in the art for a satellite broadcast system that can be expanded. It can also be seen that there is a need in the art for a satellite broadcast system that utilizes pre-existing household cabling to minimize cost and increase flexibility in arrangement of the system components.